Novel sulfonyldiazomethane compounds, photoacid generator, resist materials and patterning process using the same

Abstract

Provided are sulfonyldiazomethane compounds and photoacid generators suited for resist materials which generate less foreign matters after application, development and peeling, and in particular, are excellent in the pattern profile after the development; and resist materials and patterning process using them. Provided are sulfonyldiazomethane compounds represented by formula (1): Also provides are photoacid generators containing the sulfonyldiazomethane compounds, and a chemical amplification resist material comprising (A) a resin which changes its solubility in an alkali developer by action of an acid, and (B) a sulfonyldiazomethane compound of formula (1) capable of generating an acid by exposure to radiation. Provided is a patterning process comprising steps of applying the above-described resist material onto a substrate to form a coating, heating the coating, exposing the coating, and developing the exposed coating in a developer after an optional heat treatment.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to Japanese Patent Application No. 2003-304060, filed Aug. 28, 2003, the disclosure of which is incorporated herein by reference in its entirely. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to sulfonyldiazomethane compounds suited for chemical amplification resist materials for the fabrication of integrated circuits or the other electronic devices which are sensitive to radiation such as UV, deep UV, electron beams, x-rays, excimer laser beam, γ-rays, and synchrotron radiation; photoacid generators for resist materials; and resist materials comprising the sulfonyldiazomethane, and a patterning process using the material. 2. Description of the Related Art As a finer pattern rule is requested in the trend of higher integration and higher speed of LSI, deep-ultraviolet lithography is regarded promising as a microfabrication technology of next generation. In recent days...

AI Technical Summary

Benefits of technology

Although the amount of the photoacid generator (C), which is other than the sulfonyldiazomethane represented by formula (1), (1a), (1a′) or (1a″) and is added to the chemical amplification resist material of the invention is not particular limited insofar as it does not impair the effects of the invention, it is preferably from 0 to 10 parts by weight, more preferably from 0 to 5 parts by weight per 100 parts by weight of the solid content in the resist material. Excessively large amounts may cause deterioration in resolution or a problem of foreign matters upon development / resist peeling. The above-described photoacid generator (C) may be used singly or in combination of two or more. The transmittance of the resist film can be controlled by using a photoacid generator having a low transmittance at the exposure wavelength and adjusting its amount upon addition.

, it is preferably from 0 to 10 parts by weight, more preferably from 0 to 5 parts by weight per 100 parts by weight of the solid content in the resist material. Excessively large amounts may cause deterioration in resolution or a problem of foreign matters upon development / resist peeling. The above-described photoacid generator (C) may be used singly or in combination of two or more. The transmittance of the resist film can be controlled by using a photoacid generator having a low transmittance at the exposure wavelength and adjusting its amount upon addition.

The resist material of the invention may further contain a compound which is decomposed to generate an acid by the action of an acid. Such a compound is called “acid proliferating compound” and described in J. Photopolym. Sci. and Tech., 8, 43-44, 45-46(1995), and J. Photopolym. Sci. and Tech., 9, 29-30(1996).

Examples of the acid proliferating compound include, but not limited to, tert-butyl-2-methyl-2-tosyloxymethyl acetoacetate and 2-phenyl-2-(2-tosyloxyethyl)-1,3-dioxolane. Of the known photoacid generators, compounds poor in stability, particularly in thermal stability, tend to behave like the acid proliferating compound.

The amount of the acid proliferating compound to be added to the resist material of the invention comprising the sulfonyldiazomethane as a photoacid generator is preferably 2 parts by weight or less, more preferably 1 part by weight or less per 100 parts by weight of the solid content in the resist material. Excessive addition of it may make diffusion control difficult, tending to cause deterioration in resolution and pattern shape.

As the basic compound serving as component (D), a compound capable of suppressing a diffusion rate of an acid generated by a photoacid generator in a resist film is suited. By incorporating such a basic compound, the diffusion rate of an acid in a resist film can be suppressed, leading to an improvement in resolution. In addition, it can suppress a change in sensitivity after exposure and reduce dependence on the substrate or environment, and thereby can improve the exposure latitude and the pattern profile.

Problems solved by technology

The conventional photoacid generators, especially diazodisulfone ones do not satisfy all of these requirements.

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